> ## Documentation Index
> Fetch the complete documentation index at: https://hedera-0c6e0218-mintlify-bc559771.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Java Quickstart

> Install the Hedera Java SDK with Maven or Gradle, configure testnet operator credentials, query your account balance, and submit an HBAR transfer transaction.

This page gets a Java application talking to Hedera testnet: SDK install, operator credentials, balance query, and an HBAR transfer.

## Prerequisites

* JDK 11 or later
* Maven 3.8+ or Gradle 8+
* A Hedera testnet account with ECDSA keys from the [developer portal](https://portal.hedera.com)

## Step 1: Add the SDK dependency

For Maven, add to `pom.xml`:

```xml theme={null}
<dependencies>
    <dependency>
        <groupId>com.hedera.hashgraph</groupId>
        <artifactId>sdk</artifactId>
        <version>2.72.0</version>
    </dependency>
    <dependency>
        <groupId>io.grpc</groupId>
        <artifactId>grpc-netty-shaded</artifactId>
        <version>1.73.0</version>
    </dependency>
</dependencies>
```

For Gradle, add to `build.gradle`:

```groovy theme={null}
dependencies {
    implementation 'com.hedera.hashgraph:sdk:2.72.0'
    implementation 'io.grpc:grpc-netty-shaded:1.73.0'
}
```

`grpc-netty-shaded` is the network transport. Without it the SDK compiles, then throws at runtime when you actually try to talk to the network.

## Step 2: Credentials

Create a `.env` file in your project root (and add it to `.gitignore`):

```dotenv theme={null}
OPERATOR_ID=0.0.1234
OPERATOR_KEY=302d300706052b8104000a032200033456...
```

`OPERATOR_ID` is your Hedera account ID. `OPERATOR_KEY` is the DER-encoded ECDSA private key; use the **HEX Encoded Private Key** value from the developer portal.

## Step 3: Connect, query, transfer

Create `src/main/java/HederaQuickstart.java`:

```java theme={null}
import com.hedera.hashgraph.sdk.*;
import io.github.cdimascio.dotenv.Dotenv;

public class HederaQuickstart {

    public static void main(String[] args) throws Exception {
        Dotenv env = Dotenv.load();
        AccountId operatorId = AccountId.fromString(env.get("OPERATOR_ID"));
        PrivateKey operatorKey = PrivateKey.fromString(env.get("OPERATOR_KEY"));

        // Connect to testnet using the operator account as the default payer.
        Client client = Client.forTestnet();
        client.setOperator(operatorId, operatorKey);

        // 1. Query the operator's balance.
        Hbar balance = new AccountBalanceQuery()
            .setAccountId(operatorId)
            .execute(client)
            .hbars;
        System.out.println("Operator balance: " + balance);

        // 2. Transfer 1 HBAR to account 0.0.3 (a test recipient).
        AccountId recipient = AccountId.fromString("0.0.3");
        TransactionResponse response = new TransferTransaction()
            .addHbarTransfer(operatorId, Hbar.from(-1))
            .addHbarTransfer(recipient, Hbar.from(1))
            .execute(client);

        TransactionReceipt receipt = response.getReceipt(client);
        System.out.println("Transfer status: " + receipt.status);
        System.out.println("Transaction ID: " + response.transactionId);

        client.close();
    }
}
```

Add a `.env` loader to your dependencies if you don't have one. `io.github.cdimascio:dotenv-java:3.0.0` is the common pick.

## Step 4: Run it

```bash theme={null}
# Maven (package as a JAR with dependencies, then run it)
mvn package
java -cp target/your-artifact-with-dependencies.jar HederaQuickstart

# Gradle
./gradlew run
```

Expected output:

```text theme={null}
Operator balance: 10000 ℏ
Transfer status: SUCCESS
Transaction ID: 0.0.1234@1700000000.123456789
```

Look up the transaction on HashScan:

```text theme={null}
https://hashscan.io/testnet/transaction/<transactionId>
```

## What's next

<CardGroup cols={2}>
  <Card title="Create an Account" icon="user-plus" href="/native/accounts/create">
    Generate a new account programmatically and fund it from your operator.
  </Card>

  <Card title="Create a Token" icon="coins" href="/native/tokens/define">
    Mint a native HTS token with custom supply and decimals.
  </Card>

  <Card title="Submit to a Topic" icon="comment" href="/native/consensus/submit-message">
    Publish a message to HCS for verifiable, ordered audit logs.
  </Card>

  <Card title="SDK Reference" icon="book" href="https://github.com/hiero-ledger/hiero-sdk-java">
    Full API reference on GitHub.
  </Card>
</CardGroup>

<Tip>
  The four Hiero SDKs (JavaScript, Java, Go, Python) share the same API surface, so code translates almost line-for-line between them. Differences are mostly language-idiomatic.
</Tip>